Reference Radiograph Generation via 4D-CBCT Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for predicting and tracking patient tissue motion during radiation therapy, such as 4D-CT and 4D-CBCT, face limitations in accuracy and precision due to the assumption of regular respiratory motion and the need for implanted fiducial markers, which can be invasive and interfere with treatment beams.
Innovation Solution
A method involving a 4D-CBCT apparatus and a radiographic apparatus to generate and correlate CBCT images with radiographs at equivalent temporal phases, creating a reference radiograph for precise comparison during treatment, eliminating the need for implanted markers and reducing computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If 4D-CT is performed to generate CT images at different times for predicting tissue motion, then motion prediction capability is improved, but the accuracy deteriorates because it cannot accurately represent motion during treatment due to time delay of one to two weeks
Solution Approach 1:
The patent performs a radiographic sequence and correlates radiographs with CBCT images to create reference radiographs before treatment. This preliminary action captures the actual tissue geometry and position just before treatment, eliminating the time delay problem of 4D-CT while establishing a reference for motion tracking during treatment.
2Measurement precision
If implanted fiducial markers are used for direct tissue tracking during treatment, then measurement precision is improved, but object-affected harmful factors worsen due to infection risks, pneumothorax risks, marker migration, and interference with treatment beams
Solution Approach 1:
The patent extracts the tracking function from physical implanted markers and transfers it to image correlation. By comparing radiographs taken during treatment with reference radiographs derived from CBCT images, the system achieves markerless tissue tracking, eliminating all harmful effects of marker implantation while maintaining tracking precision.
3Adaptability or versatility
If 4D-CBCT is performed to generate CBCT images at different angular positions for tissue tracking, then adaptability is improved by enabling treatment room installation, but device complexity worsens due to the requirement of positioning source and detector at different angular positions
Solution Approach 1:
The patent creates a copy of the treatment geometry by acquiring CBCT images at multiple angular positions and correlating them with radiographs. This copying approach allows the system to capture three-dimensional tissue information without requiring complex real-time angular positioning during treatment, simplifying the operational complexity while maintaining adaptability.
4Ease of operation
If DRRs are generated by numerically projecting CBCT or CT images on a planar surface for tissue tracking, then ease of operation is improved by enabling reference creation, but manufacturing precision deteriorates due to loss of information from numerical projection operations
Solution Approach 1:
The patent merges the advantages of CBCT imaging with radiographic projection by directly correlating radiographs with CBCT images at equivalent temporal phases. This merging approach creates reference radiographs that retain the high quality of CBCT data while providing the ease of radiographic comparison, avoiding the information loss inherent in traditional DRR generation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of tissue tracking during radiation therapy by providing a precise reference radiograph for comparison, reducing patient dose, and eliminating the need for implanted markers, allowing for more precise delivery of treatment beams.
Implementation Method 1
a source and a detector that can be positioned at different angular positions around a patient, said 4D-CBCT apparatus being able to generate a plurality of CBCT images corresponding to different times
Implementation Method 2
a radiographic apparatus comprising a radiographic source and a radiographic detector and configured for generating a sequence of radiographs corresponding to different times
Data Source
AI summary
Disclosed systems and methods may include an imaging system. The imaging system may include a 4D-CBCT apparatus able to generate a plurality of CBCT images corresponding to different temporal phases. The imaging system may also include a radiographic apparatus able to generate a radiograph. Further, the imaging system may include a synchronization device for correlating a radiograph of said radiographic apparatus with a CBCT image generated by said 4D-CBCT apparatus, such that a reference radiograph can be determined.